<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Filter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: StringToLower.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Filter_Interface
 */
require_once 'Zend/Filter/Interface.php';

/**
 *
 * @category Zend
 * @package Zend_Filter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Filter_StringToLower implements Zend_Filter_Interface {

    /**
     * Encoding for the input string
     * @var string
     */
    protected $_encoding = null;

    /**
     * Constructor
     * @param string|array|Zend_Config $options OPTIONAL
     */
    public function __construct ($options = null) {
        if ($options instanceof Zend_Config) {
            $options = $options -> toArray ();
        } else 
            if ( ! is_array ($options)) {
                $options = func_get_args ();
                $temp = array();
                if ( ! empty ($options)) {
                    $temp['encoding'] = array_shift ($options);
                }
                $options = $temp;
            }
        if ( ! array_key_exists ('encoding', $options) && function_exists ('mb_internal_encoding')) {
            $options['encoding'] = mb_internal_encoding ();
        }
        if (array_key_exists ('encoding', $options)) {
            $this -> setEncoding ($options['encoding']);
        }
    }

    /**
     * Returns the set encoding
     * @return string
     */
    public function getEncoding () {
        return $this -> _encoding;
    }

    /**
     * Set the input encoding for the given string
     * @param string $encoding
     * @return Zend_Filter_StringToLower Provides a fluent interface
     * @throws Zend_Filter_Exception
     */
    public function setEncoding ($encoding = null) {
        if ($encoding !== null) {
            if ( ! function_exists ('mb_strtolower')) {
                require_once 'Zend/Filter/Exception.php';
                throw new Zend_Filter_Exception ('mbstring is required for this feature');
            }
            $encoding = (string) $encoding;
            if ( ! in_array (strtolower ($encoding), array_map ('strtolower', mb_list_encodings ()))) {
                require_once 'Zend/Filter/Exception.php';
                throw new Zend_Filter_Exception ("The given encoding '$encoding' is not supported by mbstring");
            }
        }
        $this -> _encoding = $encoding;
        return $this;
    }

    /**
     * Defined by Zend_Filter_Interface
     * Returns the string $value, converting characters to lowercase as necessary
     * @param string $value
     * @return string
     */
    public function filter ($value) {
        if ($this -> _encoding !== null) {
            return mb_strtolower ((string) $value, $this -> _encoding);
        }
        return strtolower ((string) $value);
    }

}
